Answer this question truthfully
### Question: What causes Birthmarks-red?
### Response: There are two main categories of birthmarks.
Red birthmarks are made up of blood vessels close to the skin surface, and are called vascular birthmarks. Pigmented birthmarks are areas in which the color of the birthmark is different from the color of the rest of the skin.
Hemangiomas are a common vascular birthmark. Their cause is unknown. The color results from the development of blood vessels at the site.
Strawberry hemangiomas (strawberry mark, nevus vascularis, capillary hemangioma, hemangioma simplex) may develop several weeks after birth. Cavernous hemangiomas (angioma cavernosum, cavernoma) are similar to strawberry hemangiomas but they are deeper. Salmon patches (stork bites) are extremely common, appearing on 30-50% of newborns. A port-wine stain is a flat hemangioma made of dilated blood capillaries. Port wine stains on the face may be associated with Sturge-Weber syndrome.